1. Field of the Invention
The present invention relates to articulated structures and, more particularly, to a modular articulated structure suited for use as a robot skeleton.
2. Description of the Prior Art
In the prior art it is known to have robot systems that are modular, reconfigurable and expandable to thus improve the flexibility and versatility thereof. For instance, U.S. Pat. No. 5,523,662 issued to Goldenberg et al. on Jun. 4, 1996, discloses a manipulator arm formed of a number of independent rotary joints releasably connected to each other by means of elongated connector members. The manipulator arm may be disassembled and reassembled in order to obtain different arm configurations. More particularly, each joint generally includes a L-shaped member and an inverted U-shaped member pivotally movable with respect to the L-shaped member. A motor having a drive shaft is mounted to the L-shaped member for pivoting the inverted U-shaped member relative to the L-shaped member. The inverted U-shaped member includes a pair of opposed downwardly extending connecting plates that are pivotally connected respectively to an upwardly extending portion of the L-shaped member and to the drive shaft of the motor. Accordingly, the U-shaped member is supported by both the L-shaped member and the drive shaft of the motor, whereby the drive shaft is submitted to workloads and static loads, and thus the overall structural rigidity of the manipulator arm is compromised.
Therefore, it would be advantageous to provide a rotary joint having a motor that is configured and positioned to transmit a pivotal force without supporting any load other than the rotational load.
Furthermore, the aforementioned L-shaped and inverted U-shaped members do not provide support to each other at certain relative positions thereof which would increase the rigidity of the above described flexible manipulator arm in these positions, as this increased rigidity may be required to accomplish particular tasks.
It would also be very suitable to have a modular robot structure wherein each module is provided with mating electrical connectors, such as pin connectors, to enable quick connection and disconnection of adjacent modules.
Finally, it would also be very suitable to have a flexible modular arm structure offering increased flexibility while occupying as little room as possible.
It is therefore an aim of the present invention to provide a compact rotary module forming part of an articulated structure and having an actuator which is essentially not submitted to loads other than the rotational loads induced by the actuator itself.
It is also an aim of the present invention to provide a robot system having a flexible architecture.
It is also an aim of the present invention to provide a displaceable robot system which is adapted to evade obstacles and which offers increase manoeuvrability.
It is a further aim of the present invention to provide a flexible architecture that is modular, expandable and reconfigurable.
It is a still further aim of the present invention to provide a flexible architecture that is designed to offer ease of assembly and disassembly.
It is a still further aim of the present invention to provide a flexible robot structure, which is adapted to be configured to provide sufficient structural rigidity to perform a particular task.
It is a still further aim of the present invention to provide a robot system, which provides a relatively lightweight structure.
It is a still further aim of the present invention to provide a robot system, which is relatively simple and economical to manufacture.
Therefore, in accordance with the present invention, there is provided a module for forming a segment of an articulated robot structure, comprising first and second structural members, an axle for pivotally mounting said second structural member to said first structural member, an actuator for pivoting said second structural member relative to said first structural member, a sensor for sensing a position of said second structural member, and a control unit connected to said sensor for controlling movements of said second structural member, wherein said first and second structural members each include a base plate and a pair of spaced-apart side plates extending from said base plate, said base plates of said first and second structural members each including attachment means for releasably attaching said module to respective adjacent modules, and wherein said module is provided with a communication interface for allowing said module to communicate with adjacent modules, said communication interface being connected to said control unit for allowing control commands to be fed through a given number of assembled modules.
Also in accordance with the present invention, there is provided a flexible snake robot comprising a number of serially interconnected rotary modules, each rotary module including first and second structural members pivotally connected together, an actuator for pivoting said second structural member relative to said first structural member, a sensor for sensing an angular position of said second structural member relative to said first structural member, a controller operatively connected to said sensor for operating said actuator, wherein said flexible snake robot has first and second opposed free ends, said first and second opposed free ends being interconnectable, and wherein said flexible snake robot is configurable into a loop with said first and second free ends thereof releasably interconnected to form an endless chain of modules.
Further in accordance with the present invention, there is provided a module for forming a segment of an articulated structure, comprising first and second structural members pivotally mounted together, said first and second structural members having cooperating abutting surfaces radially arranged relative to an axis of rotation of said module so as to continuously remain tangential to one another while said second member is pivoted relative to said first structural member, thereby providing continuous radial bearing contact between said first and second structural members such that a load on said module is supported substantially entirely by said bearing surfaces of said first and second structural members.
Still further in accordance with the present invention, there is provided a walking robot structure comprising a series of rotary modules assembled in line and having a first terminal module at a first end thereof and a second terminal module at a second opposed end thereof, each rotary module having first and second structural members pivotally connected to one another for rotation about a pivot axis and being operated by an actuator, said first and second terminal modules each having an axle extending generally in parallel to a longitudinal axis of said series, and a riding disc mounted on each of said axles laterally outwardly of said series, said riding disc having a circumferential surface adapted to ride on a support surface when said rotary modules are displaced in a rigid axle configuration and a lateral outer surface adapted to serve as a base surface for allowing said walking robot structure to walk on said lateral outer surfaces of said riding discs when said rotary modules are rotated relative to one another.
Still further in accordance with the present invention, there is provided a movable robot structure comprising a pair of riding discs mounted on respective secondary axles extending axially outwardly from opposed ends of an articulated main axle, said articulated main axle including a number of serially connected rotary modules having respective pivot axes extending perpendicularly to said secondary axles, and wherein each of said rotary modules is operated by an actuator controlled by a control unit.
Still further in accordance with the present invention, there is provided a flexible elongated structure comprising a series of rotary modules detachably assembled in a chain-like configuration, each rotary module including a hollow joint having an internal free space for housing at least one component, said hollow joint including first and second structural members, each of said first and second structural members being provided with a pair of spaced-apart side plates extending from a base plate, said side plates of said second structural member being received between said side plates of said first structural member and pivotally connected thereto so that said second structural member is pivotable relative to said first structural member about an axis perpendicular to said side plates, and rigid connections for releasably attaching adjacent pairs of rotary modules.
Still further in accordance with the present invention, there is provided an article handling/supporting structure comprising a vertical mounting column, a cantilever flexible arm having a first end connected to said vertical column and a second opposed end adapted to carry an article, said cantilever flexible arm being vertically displaceable between fixed positions along said vertical column and including a number of serially interconnected rotary modules, each rotary module including first and second structural members, a vertical axle pivotally connecting said first and second structural members together so that adjacent modules are rotatable with respect to each other in a horizontal plane while being prevented from rotational movement in a vertical plane under gravitational forces, thereby providing for a self-supported flexible arm.
Still further in accordance with the present invention, there is provided a flexible arm for use in a three dimensional coordinate measuring device, said flexible arm being supported at a first end thereof and carrying a probe at a second opposed end thereof, said flexible arm comprising:
a series of rotary modules assembled together in a chain-like configuration so that said series is movable within a given volume,
each of said rotary modules including a hollow joint defined by first and second structural members pivotally mounted together in opposed facing relationship for pivotal movement about an axis perpendicular to a longitudinal axis of said series of rotary modules, and a sensor for providing rotational positioning data on each of said rotary modules, and
a rigid connection between each pair of adjacent rotary modules to releasably attach the second structural member of a first rotary module to the first structural member of a second rotary module.
Still further in accordance with the present invention, there is provided a flexible robot limb comprising a number of serially interconnected rotary modules, each rotary module including first and second structural members pivotally connected together, an actuator for pivoting said second structural member relative to said first structural member, a sensor for sensing an angular position of said second structural member relative to said first structural member, a controller operatively connected to said sensor for operating said actuator, and wherein a number of said rotary modules further includes a break selectively acting on said second structural members thereof to releasably lock a segment of said flexible robot limb in a rigid state while allowing other segments of said robot limb to remain flexible.